墩-桥体系的地震弹塑性（II）：工程应用与参数敏感性分析.docVIP

差动激励下海床-桩-墩-桥体系的地震弹塑性（II）： 柳国环12，等 （1. 天津大学，建筑工程学院，天津，300072；2. 清华大学，土木水利学院，北京，100084） 摘要：首先，建立大跨海床地基-桩-墩-桥结构体系空间数值模型，包括粘弹性人工边界、悬索找形几何非线性、桩-土接触非线性以及钢筋混凝土材料非线性。其次，计算和对比考虑地基和人工边界条件与否的三种结构体系模态。同时，生成地基输入位置的多点地震动。然后，重点在性质考察构件进入塑性对地震输入空间变异性，人工边界条件和接触非线性的敏感性；进而，量化给出拟静力与动力反应贡献比例，认识体系塑性铰出现时间、位置及其分布规律。结果表明：（1）结构体系的水动质量与人工边界条件影响不容忽视；（2）塑性铰对于一致与差动输入敏感，影响分布规律和破坏模式；（3）拟静力影响源于不均匀输入导致的反应不一致性，动力作用影响源于频谱；（4）随地震强度加大，塑性反应对接触非线性的敏感性加强，破坏为严重。 关键词：跨海大桥；粘弹性人工边界；多点地震动；塑性铰；破坏模式；拟静力 Elasto-plasticity Analysis of Bridge Accounting for Spatial Variability of Earthquake Motion and Seabed-pile-piers-bridge Interaction Part (II): Application and Parameter Sensitivity Analysis Liu Guohuan1,2，etc (1. School of Civil Engineering, Tianjin University, Tianjin, 300072; 2.Department of Civil Engineering, Tsinghua University, Beijing, 100084） Abstract: A three-dimensional finite element model of large-span seabed-pile-piers-bridge is established. In the model, the visco-elastic artificial boundary condition, form-finding of suspension-cable for the geometric nonlinearity, pile-soil contact and material nonlinearity are considered. The modal analysis of the bridge system considering soil and artificial boundary condition or not are conducted and compared. The multiple-point earthquake motions at underground location are generated and verified. Then, the sensitivity analysis about the plastic hinges occurrence and distribution to the variability of spatial earthquake motions, artificial boundary condition and contact nonlinearity are analyzed in detail. While, relative contribution of pseudo-static and dynamic to the total response are analyzed and given. Further, location and distribution regularity including the occurrence time of plastic hinges are fully recognized. Results show that (1) The effect of soil and artificial boundary on structural response is significant and not be ignored; (2) The plastic hinges distribution regulation and failure mode are very sensitive to uniform and multiple-point ear